The present invention relates to an apparatus and method for increasing blood flow through an obstructed blood vessel and, more particularly relates to an apparatus and method for removal of at least a portion of an obstruction such as a clot from an obstructed blood vessel for treatment of ischemic stroke.
A common treatment for ischemic stroke is the use of a thrombectomy device to physically remove an obstruction such as a blood clot from the affected artery. One such thrombectomy device typically is advanced through a microcatheter into the vasculature, and is deployed into an obstruction or clot in the vasculature by pulling back on the microcatheter, allowing the thrombectomy device to capture at least a portion of the obstruction or clot, and the thrombectomy device is then retrieved by withdrawing the thrombectomy device into a catheter such as a guide catheter or an intermediate catheter. To prevent the loss of the captured portion of the obstruction or clot when the thrombectomy device is being retrieved, a balloon guide catheter or aspiration catheter may be used. Aspiration is performed by attaching a syringe to a proximal end of the guide catheter and pulling a vacuum in the syringe, while simultaneously pulling the retrieving the thrombectomy device and the captured portion of the obstruction or clot into the guide catheter. A balloon guide may be inflated just prior to retrieval of the thrombectomy device and the captured portion of the obstruction or clot in order to arrest blood flow. The thrombectomy device with the captured portion of the obstruction or clot is then pulled back into the balloon guide catheter.
One embolic protection device is known that includes inner and outer tubular members and a flexible everting filter portion that is attached at one end to a distal end of the inner tubular member, and that is attached at a second end to a distal end of the outer tubular member, so that the inner and outer tubular members are movable relative to one another to position the filter portion within the body vessel. The filter portion is movable from a collapsed, everted configuration to an expanded, generally non-everted deployed configuration. The filter portion expands radially outward to engage the filter body with an enclosing vessel wall, and also allows the passage of blood cells, while preventing the passage of captured emboli or thrombi through the filter portion.
Another similar invertible filter is known that includes a guiding member configured to slidably engage a tubular filter portion that extends distally from the guiding member and is configured to evert to form a concave shape for capturing emboli, while allowing blood cells to pass through the filter portion.
Another type of device for treating a vascular condition is known that includes a graft, and first and second support members such as stents attached to distal and proximal regions of the graft. The first and second stents are deployed distally and proximally of a vascular condition, and the graft can be everted to form a pocket to trap emboli during treatment of the vascular condition.
Another device is known that includes a capturing section configured that can be inverted within a translating section by proximal movement of a leading wire when an open proximal end of the translating section engages resistance, and the size of the capturing section is reduced to enable the capturing section to re-enter a catheter.
Another device for increasing blood flow through an obstructed blood vessel is known that includes an expandable member that is positioned within a blood vessel and radially adjacent to at least a portion of an obstruction, and that is expanded to bring at least a portion of the expandable member into contact with the obstruction. The expandable member is made of a mesh having a plurality of interstices that allow one or more fragments of the obstruction to pass into and be retained within the expandable member when an outward radial force is exerted on the obstruction by the expandable member.
However, whenever a captured obstruction or clot is retrieved into any type of catheter there is always a risk of some or all of the obstruction or clot being released into a patient's vasculature. In many cases some or all of the obstruction or clot is captured on the outside of the thrombectomy device. As the thrombectomy device is pulled back into a catheter, some or all of the obstruction or clot may be scraped off, sending one or more pieces of the obstruction or clot downstream to another artery, after which one or more dislodged pieces of the obstruction or clot will then need to be removed, adding to the length of time and complexity of the procedure. Smaller pieces of the clot also may go further downstream to smaller vessels that are not accessible with current thrombectomy devices.
It would be desirable to provide an apparatus and method for removal of at least a portion of an obstruction or clot from an obstructed blood vessel for treatment of ischemic stroke that provides a cover over the secured obstruction or clot prior to drawing the secured obstruction or clot into a catheter, in order to reduce the risk of the obstruction or clot being scraped off or otherwise losing one or more pieces of the obstruction or clot being retrieved during a thrombectomy procedure. The present invention meets these and other needs.